Methods for using a detector to monitor and detect channel occupancy

• US 9,288,684 B2
• Filed: 06/10/2013
• Issued: 03/15/2016
• Est. Priority Date: 10/18/2006
• Status: Expired due to Fees

• Current Assignee: Shared Spectrum Company
• Original Assignee: Shared Spectrum Company
• Inventors: McHenry, Mark Allen, Dain, Dmitry, Livis, Eugene, Steadman, Karl, Ritterbush, Olga
• Primary Examiner(s): JAIN, RAJ K
• Application Number:
  US13/914,038
• Publication Number:
  US 20130273957A1
• Time in Patent Office: 1,009 Days
• Field of Search: 370/217, 370/221, 370/503, 709/232, 709/233, 709/234, 710/100, 710/109
• US Class Current: 1/1
• CPC Class Codes: H04B 17/14 of the whole transmission and reception path, e.g. self-test loop-back
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04B 7/0647 Variable feedback rate
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 56/003 Arrangements to increase tolerance to errors in transmission or reception timing
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

Methods for using a detector to monitor and detect channel occupancy are disclosed. The detector resides on a station within a network using a framed format having a periodic time structure. When non-cooperative transmissions are detected by the network, the detector assesses the availability of a backup channel enabling migration of the network. The backup channel serves to allow the network to migrate transparently when the current channel becomes unavailable. The backup channel, however, could be occupied by another network that results in the migrating network interfering with the network already using the backup channel. Thus, the detector detects active transmission sources on the backup channel to determine whether the backup channel is occupied. Methods for using the detector include scheduling detection intervals asynchronously. The asynchronous detection uses offsets from a reference point within a frame.

Claims

1. A method of operating a network station, the method comprising:

determining a framing of a cooperative network transmission on a first frequency;

scheduling an asynchronous detection interval within a frame defined by the identified framing of the cooperative network;

detecting for non-cooperative transmissions on the first frequency during the asynchronous detection interval, the non-cooperative transmissions originating from a source not participating in the cooperative network;

detecting for non-cooperative transmissions on a second frequency;

determining that the first frequency is occupied based upon a presence of a non-cooperative transmission detected on the first frequency;

determining that the second frequency is not occupied based upon an absence of non-cooperative transmissions detected on the second frequency;

tuning a receiver to the second frequency responsive to information regarding occupancy of the first and second frequencies; and

receiving a transmission from a cooperative network station on the second frequency.

2. The method of claim 1, wherein the step of detecting for non-cooperative transmissions on the second frequency occurs during a portion of the framing of the cooperative network during which at least one other network station in the cooperative network is scheduled to send or receive a transmission on the first frequency.

3. The method of claim 1, further comprising:

sending information regarding the presence of non-cooperative transmissions on the first frequency to a base station; and

receiving information about the second frequency from the base station.

4. The method of claim 3, wherein the information about the second frequency from the base station comprises an instruction to tune the receiver to the second frequency.

5. The method of claim 1, wherein the network station comprises a wireless spectrum detector and the receiver.

6. The method of claim 1, wherein the network station comprises a plurality of wireless spectrum detectors.

7. The method of claim 1, wherein the step of determining the framing of the cooperative network transmission comprises receiving a definition of the framing.

8. The method of claim 1, wherein the step of detecting for non-cooperative transmissions on the second frequency is performed during the scheduled asynchronous detection interval.

9. The method of claim 1, wherein the step of detecting for non-cooperative transmissions on the second frequency is performed during a transmission gap.

10. The method of claim 1, wherein the step of detecting for non-cooperative transmissions on the second frequency is performed during a portion of the frame that is non-overlapping with a transmission gap within the frame.

11. The method of claim 1, wherein the framing includes a transmission gap within the frame.

12. The method of claim 11, further comprising the step of scheduling the transmission gap for each of a plurality of stations in the network.

13. The method of claim 1, wherein the step of scheduling includes scheduling a start of the detection interval within the frame.

14. The method of claim 1, wherein the non-cooperative transmissions originate from a source that is not capable of participating in the cooperative network.

15. The method of claim 1, wherein the network station and the source of the non-cooperative transmissions are not in communication with any common network station.

16. A method of operating a network station, the method comprising:

detecting for non-cooperative wireless transmissions on a current channel with a wireless detector;

scheduling a first asynchronous detection interval within a frame, wherein the first asynchronous detection interval is non-overlapping with a transmission gap within the frame;

scheduling a second asynchronous detection interval within the frame, wherein the second asynchronous detection interval is non-overlapping with the first asynchronous detection interval, and the second asynchronous detection interval is non-overlapping with the transmission gap within the frame; and

detecting for presence of transmissions on a backup channel during at least one interval selected from;

the first asynchronous detection interval and the second asynchronous detection interval.

17. The method of claim 16, further comprising a step of determining that the backup channel is occupied by a non-cooperative transmission based upon the detecting step.

18. The method of claim 16, further comprising a step of receiving a time frame format, the time frame format specifying the location of the transmission gap within the frame.

19. The method of claim 16, further comprising:

responsive to detecting the non-cooperative wireless transmission on the current channel, migrating a communication network to the backup channel.

20. The method of claim 16, further comprising:

detecting presence of transmissions on a second backup channel with the wireless detector during the first asynchronous detection interval.

21. The method of claim 16, wherein the network station comprises the wireless detector.

22. The method of claim 21, wherein the network station comprises a separate wireless receiver.

23. The method of claim 16, wherein the network station is in a cooperative network with at least one other network station having a wireless detector and a wireless receiver separate from the wireless detector.

24. A network station comprising:

a wireless spectrum detector configured to detect for non-cooperative transmissions on a first frequency during an asynchronous detection interval scheduled within a frame defined by a framing of a cooperative network the non-cooperative transmissions originating from a source not participating in the cooperative network, and further configured to detect for non-cooperative transmission on a second frequency;

wherein the network station is configured to;

determine that that the first frequency is occupied based upon a presence of a non-cooperative transmission detected on the first frequency;

determine that the second frequency is not occupied based upon an absence of non-cooperative transmissions detected on the second frequency;

tune to the second frequency responsive to information regarding occupancy of the first and second frequencies; and

receive a transmission from a cooperative network station on the second frequency.

25. The network station of claim 24, further comprising a receiver.

26. The network station of claim 25, wherein the step of tuning to the second frequency is performed by tuning the receiver to the second frequency.

27. The network station of claim 25, wherein the receiver is separate from the wireless spectrum detector.